Findings from both cross-sectional and prospective studies have documented that increased exposure to cigarette advertising and marketing is associated with increases in adolescent smoking behavior. Despite these findings, critical questions about the effects of cigarette advertising and marketing remain unanswered: Does exposure to cigarette advertising and marketing causally contribute to adolescent smoking? Are some media more effective than others at advertising and marketing cigarettes to adolescents? Is the effect of exposure to advertising/marketing via multiple media channels stronger than the effect of exposure via a single channel? Are some groups of adolescents more at risk to the effects of cigarette advertising and marketing than others? What psychological processes mediate and moderate the effects of advertising exposure on adolescent smoking? This research will execute a randomized controlled experiment that manipulates exposure to different types of cigarette advertising/marketing and evaluates the effect of that exposure on subsequent smoking intentions in never smoking adolescents in the laboratory. We will randomly assign never smoking adolescents to one of four types of cigarette advertising exposure conditions: exposure via magazine advertising, exposure via smoking in movies, exposure via both magazine and movie advertising, or no exposure. Thus, this study will employ a 2 (magazine exposure: neutral, active) X 2 (movie exposure: neutral, active) between-subjects design. In addition, we will measure key mediating and moderating variables. The design of this experiment will allow us to answer critical questions for the field: Does exposure to cigarette advertising causally contribute to smoking intentions? Is the effect of exposure to cigarette advertising via magazines greater or lesser than the effect of exposure to cigarette advertising via movies? Are the effects of advertising via different media channels additive or interactive? What are the psychological processes through which exposure to advertising has its effects on adolescents, and what individual differences variables place adolescents at specific risk to the effects of cigarette advertising? The results of this research are critical to informing the next generation of smoking prevention and media literacy programs for adolescents. PUBLIC HEALTH RELEVANCE: Exposure to cigarette advertising (for example in magazines and movies) has been associated with increases in adolescent smoking, but the field does not know why or how exposure affects adolescents. Understanding how and why cigarette advertising affects adolescents is crucial for informing more effective smoking prevention programs aimed at adolescents. This research will experimentally investigate the joint effects of exposure to cigarette advertising in magazines and smoking in movies on never smoking adolescents'thoughts and feelings about smoking to provide answers to these how and why questions.